In his talk, psychologist Guy Winch emphasizes the importance of practicing emotional first aid to maintain psychological health, highlighting that psychological injuries like loneliness, failure, and rejection are often neglected. He argues that just as we take care of our physical health, we should develop emotional hygiene practices to combat negative feelings and build resilience. By changing our responses to emotional pain and boosting self-esteem, we can improve overall well-being and thrive as individuals and a society.